Move almost all run-make-fulldeps to run-make

They pass fine.

tests/run-make/hotplug_codegen_backend/Makefile

@@ -0,0 +1,26 @@
+include ../tools.mk
+
+# ignore-stage1
+
+# This test both exists as a check that -Zcodegen-backend is capable of loading external codegen
+# backends and that this external codegen backend is only included in the dep info if
+# -Zbinary-dep-depinfo is used.
+
+all:
+	/bin/echo || exit 0 # This test requires /bin/echo to exist
+	$(RUSTC) the_backend.rs --crate-name the_backend --crate-type dylib \
+		-o $(TMPDIR)/the_backend.dylib
+
+	$(RUSTC) some_crate.rs --crate-name some_crate --crate-type lib -o $(TMPDIR)/some_crate \
+		-Z codegen-backend=$(TMPDIR)/the_backend.dylib -Z unstable-options \
+		--emit link,dep-info
+	grep -x "This has been \"compiled\" successfully." $(TMPDIR)/libsome_crate.rlib
+	# don't declare a dependency on the codegen backend if -Zbinary-dep-depinfo isn't used.
+	grep -v "the_backend.dylib" $(TMPDIR)/some_crate.d
+	
+	$(RUSTC) some_crate.rs --crate-name some_crate --crate-type lib -o $(TMPDIR)/some_crate \
+		-Z codegen-backend=$(TMPDIR)/the_backend.dylib -Z unstable-options \
+		--emit link,dep-info -Zbinary-dep-depinfo
+	grep -x "This has been \"compiled\" successfully." $(TMPDIR)/libsome_crate.rlib
+	# but declare a dependency on the codegen backend if -Zbinary-dep-depinfo it used.
+	grep "the_backend.dylib" $(TMPDIR)/some_crate.d

tests/run-make/hotplug_codegen_backend/some_crate.rs

@@ -0,0 +1,2 @@
+#![feature(no_core)]
+#![no_core]

tests/run-make/hotplug_codegen_backend/the_backend.rs

@@ -0,0 +1,84 @@
+#![feature(rustc_private)]
+#![deny(warnings)]
+
+extern crate rustc_codegen_ssa;
+extern crate rustc_data_structures;
+extern crate rustc_driver;
+extern crate rustc_errors;
+extern crate rustc_hir;
+extern crate rustc_metadata;
+extern crate rustc_middle;
+extern crate rustc_session;
+extern crate rustc_span;
+extern crate rustc_symbol_mangling;
+extern crate rustc_target;
+
+use rustc_codegen_ssa::traits::CodegenBackend;
+use rustc_codegen_ssa::{CodegenResults, CrateInfo};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_errors::ErrorGuaranteed;
+use rustc_metadata::EncodedMetadata;
+use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
+use rustc_middle::ty::TyCtxt;
+use rustc_session::config::OutputFilenames;
+use rustc_session::Session;
+use std::any::Any;
+
+struct TheBackend;
+
+impl CodegenBackend for TheBackend {
+    fn locale_resource(&self) -> &'static str { "" }
+
+    fn codegen_crate<'a, 'tcx>(
+        &self,
+        tcx: TyCtxt<'tcx>,
+        metadata: EncodedMetadata,
+        _need_metadata_module: bool,
+    ) -> Box<dyn Any> {
+        Box::new(CodegenResults {
+            modules: vec![],
+            allocator_module: None,
+            metadata_module: None,
+            metadata,
+            crate_info: CrateInfo::new(tcx, "fake_target_cpu".to_string()),
+        })
+    }
+
+    fn join_codegen(
+        &self,
+        ongoing_codegen: Box<dyn Any>,
+        _sess: &Session,
+        _outputs: &OutputFilenames,
+    ) -> Result<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>), ErrorGuaranteed> {
+        let codegen_results = ongoing_codegen
+            .downcast::<CodegenResults>()
+            .expect("in join_codegen: ongoing_codegen is not a CodegenResults");
+        Ok((*codegen_results, FxHashMap::default()))
+    }
+
+    fn link(
+        &self,
+        sess: &Session,
+        codegen_results: CodegenResults,
+        outputs: &OutputFilenames,
+    ) -> Result<(), ErrorGuaranteed> {
+        use rustc_session::{config::CrateType, output::out_filename};
+        use std::io::Write;
+        let crate_name = codegen_results.crate_info.local_crate_name;
+        for &crate_type in sess.opts.crate_types.iter() {
+            if crate_type != CrateType::Rlib {
+                sess.fatal(&format!("Crate type is {:?}", crate_type));
+            }
+            let output_name = out_filename(sess, crate_type, &outputs, crate_name);
+            let mut out_file = ::std::fs::File::create(output_name).unwrap();
+            write!(out_file, "This has been \"compiled\" successfully.").unwrap();
+        }
+        Ok(())
+    }
+}
+
+/// This is the entrypoint for a hot plugged rustc_codegen_llvm
+#[no_mangle]
+pub fn __rustc_codegen_backend() -> Box<dyn CodegenBackend> {
+    Box::new(TheBackend)
+}